FUEL CELL SYSTEM

A supply channel through which an oxygen-containing exhaust gas discharged from a fuel cell stack is supplied to an exhaust gas combustor is branched so as to provide an oxygen-containing exhaust gas bypass channel through which the oxygen-containing exhaust gas is discharged to the outside in a manner to bypass the exhaust gas combustor. In the structure, the exhaust gas flow rate of an exhaust gas discharged through a condenser (saturated water vapor quantity) is suppressed.